Kelly bushing



March 7, 1933. w, D ID 1,899,946

KELLY BUSHING Filed March 28, 1932 2 Sheets-Sheet 1 MLLM VQ 94/105 /6March 7, 1933. w. D. DAVIDSON 1,899,946

KELLY BUSHING Filed March 28, 19:52 2 Sheets-Sheet 2 ZA/MZ/1 70EJ Z7 Mum7,0. 0414050,

#7" raw/ex Patented Mar. '7, 1933 UNITED STATES PATENT OFFICE WILLIAM D.DAVIDSON, OF LOS ANGELES, CALIFORNIA, ASSIGNOR TO EHSCO DERRICK &EQUIPMENT COMPANY, OF LOS ANGELES, CALIFORNIA, A CORPORATION CALIFORNIAKELLY resume -Application filed larch 28, 1932. Serlal ma M1558.

a My invention relates to a kelly bushing for use in providing a drivingconnection between the rotary table of a rotary machme and the kelly ordrill stem of a string of drill pipe, these elements being well known inthe oil well drilling industry.

In order that the advantages and objects of my invention may bebetterunderstood I will briefly refer to that part of the oilproducingindustry to which my invention appertains. In the drilling of an oilwell, it is common practice to set up a derrick and to place on thefloor of the derrick a rotary machine having a rotary table throughwhich the drill pipe is extended. The lower end of the drill pipe has abit provided thereon whereby the well is, drilled. The drill pipe issupported by a suitable travelling block by means of which it is feddownwardly as drilling progresses. The uppermost part of the drill pipeis ordinarily provided in the form of a drill stem or kelly which isrectangular in outer cross-section 1n order that gripping engagement maybe had therewith in order that the drill stem or kelly may be driven bythe rotary machine. At the present time it is common practice to providethe kelly bushing in the form of two parts which are set into a suitablshaped socket provided in the rotary tabl e around the opening throughwhich the drill stem is passed. The kelly bushing ordinarily employed in:the drilling art has flat faces adapted to be engaged by the flatfaces'of the drill stem or kelly. When the rotary table is rotated thekelly bushing is rotated therewith and by reason of the interengagementbetween the flat faces, the drill stem and the drill pipe securedthereto are rotated. During the drilling operation the travelling blockwhich supports the drill pipe is lowered in order that the bit securedto the lower end of the drill pipe can move downwardly as drillingoperations are continued.

It is an object of my invention to provide a kelly bushing which has abody in oneiece and which at all times remains on the elly or drillstem. It is unnecessary in my invention to remove the kelly bushing fromthe drill stem and it'is unnecessary to separately remove the kellybushing from the rotary machine, this bein automatically taken care ofby a'raising of t e drill pipe. This occurs due to the fact that at thelower end of the drill stem there is a tool joint for connecting thedrill stem to the other section of the drill pipe. This tool joint is oflarger cross-sec tional area than the drill stem and thus provides ashoulder which engages the kell bushin upon upward movement of the coumn o drill pipe, thus removing the kelly bushing from the rotary table.

It is another object of m invention to provide a kelly bushing of thecharacter mentioned in which slips are provided which may beinterchanged to suit different sizes of drill stems. It is, therefore,possible by the use of my invention to use the kelly bushing ondifferent sizes of drill stems merely by exchanging one set of slips foranother.

During the operation of the well drilling apparatus just described thetorque transmitted from the rotary table to the drill stem istransmitted through the flat faces of the slips of the kelly bushing andthe flat faces of the drill stem. Due to the fact that the rotation ofthe rotary machine is in one direction, the torque is transmitted fromthe kelly bushing to the drill stem only along one edge or along oneside of each slip' and each face ofthe drill stem, with the result thatthe wear does not take place evenly but only on one side of theinterengaging faces. As this wear continues there will be a noticeableplay between the kell bushing and the drillin which the slips may'beinverte in order that the worn portions thereof will be moved into suchpositions that they are not engaged by. the faces of the drill stem andso that the unworn ortions of the slips may be brought .into wor 'ngposition.

7 It is a still further object of my invention to provide a kellybushing which is very economical to manufacture and which may thereforebe supplied to the oil drilling industry at a relativelylow cost. Myinvention in eludes various refinements of construction whereby themachining is reduced to a minimum in order that the cost of productionwill be very low. These details of construction will be fully pointedout in the detailed description of my invention to follow.

It is a still further object of my invention to provide a novelconstruction whereby the slips may be removably held in place so thatthey may at the same time be rigidly clamped to the body of the kellybushing in order that the assembly will have the necessary strength.Other objects of my invention reside in the details of constructionwhich are conducive to simplicity and economy. These Fig. 2.

Fig. 4 is a bottom plan view of the kelly bushing of my invention.

Fig. 5 is a plan view showing a partlal assembly of the parts of myinvention.

Fig. 6 is a sectional view showing the parts in separated position anddisclosing the manner in which they are assembled on the kelly or drillstem.

Referring to the drawings and particularly to Fig. 1, the numeral 11represents the kelly bushing of my invention which is adapted to besupported by a table 12 of a rotary machine 13. Extending through thekelly bushing 11 is a kelly or drill stem 15 which is rotated. The drillstem 15 forms the upper part of the string of drill pipe 16 which issupported by a travelling block 17 and which is provided at its lowerend with a dr1llb1t 18. v The kelly'bushing is best shown 1n Flgs. 2 to5 inclusive, and in order that the details of construction of myinvention may be fully understood, reference will now be had to theseviews.

The kelly bushing includes a cast body 20 which is so designed thatthere will be but a minimum of machine work required. The body 20 iscast with a somewhat cylindrical portion 21 at the lower end-of whichthere is formed a block portion 22 having vertical faces 23 and lowerhorizontal faces 24 which are suitably machined for reception in asocket 26 provided in the rotary table 12. Formed below the block 22 isan extension 27 ofgeneral cylindrical form having an outer conical face28 which is adapted to rest in a similarly shaped opening provided inthe rotary table 12. The body 20 has a cored recess or channel 31 formedon the interior thereof, preferably in the block 22, which cored recess31 is in reeaeac communication with a passage 30 shown in the drawing.The body has a cylindrical face 33 which extends from the upper end ofthe body to a point below the cored recess 31, terminating at a shouldermeans provided -in"the form of four inwardly extending shoulders 34.

Formed on'the interior of the body from the upper end thereof downwardlyor inwardly to there being no undercutting or dovetailing required. Thecored recess 31 not only reduces the weight of the drill kelly but alsorenders the milling of the channels 35 a very simple matter, since itisinot necessary to stop the milling operation at a given point. Theslots are milled from the upper end of the body and downwardly'to thecored recess.

Adapted to placed in the body in con-' in the form ofa retaining ring38. This ring 38 has an inwardly and upwardly extending ledge 39 havingan outer upwardly tact with the shoulders 34 is a retaining means andinwardly extending conical face 40 and a flat face 41, as shown. Thepurpose of this retaining ring 38 is to retain in place the lower endsof keys 43 and slips 44.

The keys 43 have rectangular portions 45 at rest in the channels 35.Projecting inwardly from each rectangular portion 45 is a triangularportion 46 having faces 47 which extend at an angle of to each other,this angle being bisected by a radial line which extends outwardly fromthe axis of the body 20 and centrally through the key The trian larportion 46 extends outwardly below ifirectangular portion 45 and thelower end thereof is provided with an inclined or beveled face 48 whichengages the conical face 40 of the retaining ring 38. It will be seenthat the interengagement between the faces 40 and 48 will retain thelower ends of the keys 43 in place. The upper ends of the keys 43 areprovided with arcuated beveled faces 49. Adapted to be sea downwardlyextending annular projection 55 which surrounds an annular extension 56formed at the upper end of the body 20. The cover 51 has a centralopening 57, and surrounding the opening 57 is a downwardly projectingportion 58 which has a conical face 59 adapted to engage the bevelledfaces ring 38 in place.

49 of the keys- 43, thus retaining the upper engage the faces 47 of thekeys 43 and has an inner flat face 62 which extends perpendicular to aradial line extending from the axis of the body 20 through the centralpart of the slip. When the four slips 44 are positioned as shown in Fig.2 the faces 62 \cooperate to provide a rectangular passage 63 forreceiving the drill stem 15. The drill stein 15 as shown clearly in Fig.2 has four fiat faces 64, each of which is adapted to en-. gage one ofthe flat faces 62 of the slips 44.

The lower ends of the slips 44 are provided with arcuated projections 66having inner .inclined faces 67 adapted to engage the outer bevelledface 40 of the retalning ring 38,

thereby holding the lower ends of the slips 44 in place. The upper endsof the slips are provided with arcuated'projections 68 having innerinclined faces 69 which are adapted to engage the bevelled face 59 ofthe projection 58 of the cover 51. In this manner the upper ends of theslips "are retained in place.

It will be seen that but a minimum of machine work is required on thebody. The cylindrical face 33 may be very easily turned and thelongitudinal channels 35 may be economically formed, due to thefact thatthe side walls 37 thereof are parallel. In- Fig. 5 I have shown a planview of the parts of my invention partly assembled. This view clearlyshows the shape of the interior opening through the body 20.

In Fig. 6 I show the manner in which the parts are assembled. The body20 is extended over the drill stem 15 with the retaining Thecover 51 islikewise placed on the drill stem 15 and is supported m a positionspaced away from the body 20, as shown. The keys 43 are next installedin place, after which the slips 44 are installed in place. The lowerends of the keys and slips areretained against the body-by means of theretaining ring 38. After these parts have been assembled the cover 51 isthen lowered into place and the nuts 54 are advanced onto the studs 52,thus completing the assembly and thus securely locking the removableparts to the body. It will be seen that the parts are easily slippedinto place due to the fact that the assembling operation is performedaround the drill stem 15. The drill stem 15, therefore, guides the lowerends of the keys 43 and the slips 44 into place. For the convenience ofhandling the various removable parts threaded openings 73 are providedin the opposite ends of the keys and slips in order that a handlingdevice 74 may beemployed.

When once the kelly bushing is installed on the kelly or drill stem 15it is not necessary that it be removed. The kelly bushing occupies aposition as shown in Fig. 1. The

interengagement between the faces 62 of the slips 44 and the faces 64 ofthe kelly bushing I 15 provides the driving engagement which rotates thedrill pipe. Since these interengaging faces. are flat the drill pipe mabe lowered or raised, as desired, during the rilling operation. When thedrill ipe'has been lowered to such an extent thatt e upper end of thedrill stem is immediately above the kelly bushing it will then benecessary to raise the drill pipe and add another length of pipethereto. When the drill pipe is raised,

the tool joint identified by the numeral 75 which connects the drillstem to the adjacent drill pipe of the string of drill pipe 16 willengage the kelly bushing and remove it from the cavity 26 of the rotarytable 12. After the length ofdrill pipe has been installed and suitablyconnected to the drill stem 15 the parts are 2 then lowered and thekelly bushing may be guided into the cavity 26 of the rotary table 12 sothat drilling operations may be continued. I

During drilling operations the arts rotate in a direction indicated by te arrow 76 of Fig. 2. This causes the complementary faces 62 and 64 tobe in engagement along one edge at oints indicated at 7 7 All of thewear, therefbre, between the faces occurs at the portions of the faces62 and 64 indicated by the numeral 77, and no wear occurs along theopposite portions of these faces. When wear occurs to such an extentthat there is an undesirable play it is possible to remove the cover andremove and invert the slips, thus bringing the unworn portions of thefaces 62 into positions where they will be engaged by the faces 64 ofthe drill stem 15.

The device which I have described in detail accomplishes all of theobjects of my invention. The details of design are those which I preferto use. It should be strictly understood, however, that I do not wish tobe limited to the exact details of construction which I have disclosedas being preferable, since the predominating features and princi'ples-ofmy invention may be incorporated in various physical embodiments. Idesire to have my invention construed by the appended claims.

I claim as my invention: 1. In a kelly bushing for use in establishing adriving. connection between a rotary table and a drill stem, thecombination of: a body having a block portion for engagement with saidrotary table, there being an opening therethrough; a plurality of slipsdisposed in said opening; retaining means at the lower ends of saidslips; and a cover secured to the upper end of said body for immovablysecuring'the upper ends of said slips to said body.

2. In a kelly bushing for use in establishin a driving connectionbetween 'a rotary table and a drill stem, the combination of: a bodyhaving a block-portion for engagement with said rotary table, therebeing an opening through said body; shoulder means in said opening, andthere being longitudinal. channels in said body in communication withsaid opening; a retaining ring placed in said opening in contact withsaid shoulder means; keys disposed in said channels and extending intosaid opening, the inner ends of said keys engaging said retaining ring;a cover secured to an end of said body and holding said keys in saidbody; and slips. disposed in said opening between said keys.

3. In a kelly'bushing for use in establishing a driving connectionbetween a rotary table and a drill stem, the combination of: a bodyhaving a block portion for engagement with said rotary table, therebeing an opening" through said body; shoulder means in said opening,there being longitudinal channels in said body in communication withsaid open-. ing; a retaining ring placed in said opening in contact withsaid shoulder means; keys disposed in said channels and extending intosaid opening, the inner ends of said keys engaging said retaining ring;a cover secured to an end of said body and holding said keys in saidbody; and slips disposed in said openin between said keys, said slipsbeing engage by said retaining ring and said cover.

4. In a kelly bushing for use in establishing a driving connectionbetween a rotary table and a drill stem, the combination of: a bodyhaving a block portion for engagement with said rotary table, therebeing an openin through said body; shoulder means in sai opening, therebein an annular channel formed on the inner side of said body incommunication with said opening, and there being longitudinal channelsformed in said body from said annular channel to one end of said body incommunication with said opening; a retaining ring placed in said openingin contact with said shoulder means; keys disposed in said channels andextending into said opening, the inner ends of said keys engaging saidretaining ring; a cover secured to an end of said body and holding saidkeys in said body; and slips disposed in said opening between said keys.

5. In a kelly bushing for use in establishing a driving connectionbetween a rotary table and a drill stem, the combination of: a bodyhaving a block portion for engagement with said rotary table, therebeing an opening through said body; shoulder means in said opening,there being an annular channel formed on the inner side of said body incommunication with said opening, and there beseaeee ing longitudinalchannels formed in said body from said annular channel to one end ofsaid body in communication with said opening; a retaining ring placed insaid opening in contact with said shoulder means; keys disposed in saidchannels and extending into said opening, the inner ends of said keysengaging said retaining ring; a cover secured to an end of said body andholding said keys in said body; and slips disposed in said openingbetween said keys, said slips being engaged by said retaining ring andsaid cover.

6. In a kelly bushing for-use in establishing a driving connectionbetween a rotary table and a drill stem, the combination of:

a body having an external formation whereby same may be secured to saidrotary table in driving relation thereto, there being an open ingthrough said body; key means extending inwardly from said body into saidopening; sliprmembers disposed in said opening between saidkey'means,'said slip members providing a passage adapted to receive saiddrill stem; and means engaging the ends of said slip members for holdingsame in place in said body.

7 In a kelly bushing for use in establishsaid body, said means havingshoulders for holding said slip members outwardly against said body.

8. In a kelly bushing for use in establishing a driving connectionbetween a rotary table and a drill stem, the combination of: a bodyhaving an external formation whereby same may be secured to said rotarytable in driving relation thereto, there being an annular opening formedthrough said body; slip members disposed in said opening and havingouter faces for engaging the wall of said body which defines saidopening, said slip members providing a passage adapted to receive saiddrill stem; means cooperating between said body and said slip membersfor restraining relative rotation between these parts; and meansengaging the ends of said slip members for holding same in place in saidbody.

9. In a kelly bushing for use in establishing a driving connectionbetween a rotary table and a drill stem, the combination of: abodyhaving an external formation whereby same may be secured to said rotarytable in driving relation thereto, there'being an annular o ening formedthrough said body; slip mem ers disposed in said opening andhaving outerfaces for engaging the wall of said body which defines said opening,said 5 slip members providing apassage a apted to receive said drillstem; means cooperating between said body and said slip members forrestraining relative rotation between these parts; and means engagingtheends of said ,10 slip members for holding same in place in said body,said means having shoulders forholding said slip members outwardlyagainst said body.

10. In a kelly bushing for use in establish- 1 ing a driving connectionbetween a rotary table and a drill stem, the combination of: a bodyhaving a formation for driving engage- I ment with a rotary table, therebeing an open-- ing through said body, and there being a- 2 shouldertherein; a plurality of slips in said opening; retaining means inengagement with said shoulder and the lower endsof said slips; and acover secured to said body and en- 1 gaging the upper ends of saidslips, said 25 retaining means and said cover holding said sli simmovably in place I y p I n testimony whereof, I have hereunto set myhand at Los Angeles, California, this 22 day of March, 1932.

5 WILLIAM D. DAV1])SON;

